Hello all

I was playing a fat goblin and as the overlord I played critical blow.

This attack gains a serge +3 damage

What a great basic card!!!

My question is can you use this card even if your attack failed to roll a serge to add 3 additional points of damage ? Or does the +3 damage for the serge replace the existing serge damage on the monster card? ie you need to roll a serge to use this card?

Of course you still need a surge. Critical Blow doesn't replace any of the monster's own surge, it adds another option for which to use a surge. Personal favourite is the Act II master Shadow Dragon. Roll an attack that gets 2 surges, Dark Might for +1 surge, then use the surges for total +6 dmg (CB and the other +3 from SD itself) and Fire Breath (easily 10+ dmg on several characters) . But CB is also good for monsters without any innate surge abilities (Sorcerers, Ice Wyrms).

Critical blow does not give you a surge, it only gives you an extra option to spend a surge, giving +3 damage. If you roll an X you cannot deal damage as your attack missed. If you hit and have an extra surge (or Dark Might), use it!!